Many visions of the future involve people living in the middle of the ocean. This makes all kinds of sense, since oceans make up two-thirds of the planet's surface. Plus you can live independently, free from corrupt governments and the like. The biggest question, though, is how can you go about doing this? And the good news is, there are plenty of ways to stake out some marine real estate.

Here are 10 incredible structures that could allow you to live on the ocean.

2. Seasteading

For those of you looking to escape into international waters, there's always the possibility for seasteading. And in fact, this is more reality than mere speculation. Already today there are plans to set up repurposed ocean liners (or anything else that can float on the water) where they will serve as incubators for adventurous start-ups. The basic idea is that entrepreneurs and other forward-thinking people can accomplish their goals, without all those pesky laws and taxes getting in the way. Peter Thiel and his Seasteading Institute hope to set up a base just outside of Silicon Valley where occupants can "peacefully test new ideas about how to live together." Seasteaders plan on building everything required to kick-start a new society, including hospitals, casinos, hotels, and offices. And indeed, Thiel's idea is not the only one. There have been calls for a psychedelic resort/lab seastead, and some Brits have taken it upon themselves to squat on abandoned sea-based military bases and declare sovereignty. Hail, Sealand!

3. Artificial islands

For some coastal nations looking to expand upon their existing real estate options, building an island from scratch is another valid, albeit expensive, option. Perhaps the best example of this is Dubai, the home to several artificial island projects. These artificial archipelagos are spectacularly beautiful and can accommodate the needs of tourists, the commercial sector, and even residents. They're constructed of sand drawn from the bottom of the Persian Gulf and are sprayed by the dredging ships. Dubai's Palm Islands, which are currently under construction, will feature settlements shaped like a palm tree, topped with a crescent. Once complete, they will add 520 kilometers of beaches to the city. While this all sounds spectacular, recent financial woes in the region have slowed construction. Oh, and the fact they're sinking may also pose a problem. And if all this is too pretentious for you, there's always the possibility of moving to Thilafushi Garbage Island.

4. Advanced ocean liners

Ocean liners are another interesting option. These tried-and-true marine vessels are only getting bigger and increasingly sophisticated. And the future looks particularly bright — especially in consideration of the Freedom Ship, a water-based behemoth that would boast a length of 4,500 feet, a width of 750 feet, and an astounding height of 350 feet. It would be four times larger than the Queen Mary. The Freedom Ship would essentially serve as a floating city, featuring luxurious living, an extensive duty-free international shopping mall, and 1.7 million square feet for commercial and residential occupancy. More modestly, there's the M.S. America World City, an advanced concept ocean liner that would be larger than an aircraft carrier.

5. Underwater sea resorts

But why limit yourself to living on the water when you can also live under it? This is the idea behind such projects as Hydropolis and Poseidon Mystery Island. Hydropolis is a $500 million-plus, 220-room hotel that's currently in development near Dubai in the Persian Gulf. Once complete, it will be the world's first underwater hotel. And if all goes planned, it would sit 60 feet below sea level and cost $1,500 a night. Hydropolis will feature a shopping mall, three bars — oh, and a missile defense system to guard against terrorists. Poseidon, which is also under development, is a $200 million resort that's slated to be built near Fiji. Though much smaller than Hydropolis, it will feature a spectacular view of the world's liveliest coral reefs.

6. Floating homes

Houseboats have been popular for some time now — but what if you want something more sea-worthy and, well, sexy? The need for viable floating homes is all the more important these days when considering how rising sea levels may cause the destruction of shoreline residential areas. And there are already a number of architects ready to deal with the situation. Dutch designer Koen Olthuis has devoted his company, Waterstudio, to the design of waterborne structures, including houses, garages, floating villas, and apartment buildings. There's also the work of Italian architect Giancarlo Zema. He's designed the mobile egg-shaped Trilobis, a cross between a yacht and a floating home. Retailing for $5 million, it's designed for up to six people and is powered by an environmentally-friendly combination of solar power and hydrogen fuel. Alternately, you can check out the way cool Jelly-fish 45 floating habitat, also designed by Zema.

7. Sea towers

Another option is the construction of a sea tower. Similar to the fictional structure portrayed in the film, The Life Aquatic, the tower would be based at the ocean floor and extend high over the surface. The tower could serve the needs of everyone from marine biologists right through to residents and tourists. Giancarlo Zema has put together a design for such a structure, what he calls the Neptus 60 Cliff Habitat. Built alongside a rocky cliff, the tower would contain a living area, observation deck (about 20 meter above sea level), dock, and an underwater observation globe. The tower would be equipped with an elevator and a diver lock-out option for easy in-and-out privileges.

8. Modular floating cities

But why limit ourselves to small-scale ocean ventures? Like the inhabitants of Waterworld, the future of ocean living could very well come in the form of large floating cities. Such cities could take on the form of gigantic crazy quilts comprised of smaller floating dwellings. Already today in Hong Kong there's Boat City in Aberdeen Harbor. Looking to the future, there's the possibility of creating modular self-sustaining ocean habitats. The Open_Sailing model is a good example. Designed by Cesar Harada, the environmentally friendly floating city could provide a low cost alternative compared to more larger scaled visions. In addition, this mobile city could be expanded or contracted depending on the needs of the community.

9. Space elevator base stations

The idea of living at the equatorial base station of a space elevator sounds as cool as it likely to be practical. Like a busy transportation hub at the center of a city, this unique location would allow you to live at the heart of the action. The support cable for the massive structure would be tethered right there at the station and serve as the starting and ending point for orbital missions. We're still a few decades away from constructing a space elevator — but that hasn't stopped some architects from designing their own stations. And rather than just plopping an oil rig-like structure on the ocean, their designs take aesthetic and practical considerations into account. With all this said, however, you better hope that cable doesn't snap. An untapered space elevator cable needs to sustain a length of about 5,000 kilometers of its own weight at sea level to reach a geostationary altitude of 35,786 km without yielding (a specific strength of at least 100,000 kN/(kg/m)).

10. Floating ecopolis

Finally, and perhaps the most stunningly beautiful and dramatic possibility of all, there's the potential for the floating ecopolis — or what the Belgian architect Vincent Callebaut has called the Lilypad. Designed for the Oceans 2008 conference to meet four specific environmental challenges (lack of fresh water, climate change, biodiversity, and health), Callebaut designed an ecologically friendly floating city capable of housing an astounding 50,000 people — and all in a completely self-sufficient way. The floating megastructure would produce more energy than it consumes and cleanly recycle most of its waste products. The city would be able of supporting a wide variety of plants and animals, and feature a central lagoon (which has the added effect of providing ballast). Renewal energy sources would include solar, thermal, photovoltaic, wind, hydraulic, tidal energies, and others. Yes, please.

Before signing off, I should also mention the Sea Tree, a radical concept designed by Waterstudios. It's not intended for human occupancy, but instead would serve as a safe haven for plants and animals. The hanging plant-like design would feature dozens of layers, both below and above the water. The structure would be as vibrant and verdant above the water as it would be below. The designers say that it would be useful in virtually any location, whether it be off the coast of New York City or parked in the Thames River. The design would also open an entirely new realm of architecture in which massive structures would be built for plants and animals rather than humans.